Control means for electric motors supplied with current by a generator driven by an internal combustion engine



Dec. 31, 1963 R. FAGEL CONTROL MEANS FOR ELECTRIC MOTORS SUPPLIED WITH CURRENT BY A GENERATOR DRIVEN BY AN INTERNAL COMBUSTION ENGINE Filed Nov. 10, 1960 2.50 MN $23000 mckaimzmw E4 v I ||l l I l I l I l l l I l l i I lL m2 wz oou L w L United States Patent ()fitice 3 116 420 QUNTRQL MEANS; Fllliit. EEECTREQ MQTURS Sli llLllEll) Wll'li-l CURRENT BY A GENERATUR Dl-RIWEN BY AN INTERNAL CGll/llllUSlifiN ENGINE Marcinelle, Belgium, assignor to Atelier-s de Constructions Electrigues die Charleroi, lirussels, Eelgium Filed Nov. llll, 196d, Ser. No. 68,390 Qlahns priority, appiicaiiou France Nov. 13, 1959 15 Claims. (6S1. Mil-d) This invention relates to the control of groups comprising one or more electric motors supplied with current by an electric generator driven by an internal combustion engine.

The invention has for its main objects to ensure that the internal combustion engine will always operate under optimum efficiency conditions, even at low speeds, and to utilise to the best advantage the power delivered by the generator driven by the internal combustion engine for the supply of the one or more electric motors. Another object of the invention is the measuring of the speed of the internal combustion engine by very simple means. Still another object of the invention is the provision of a device for controlling the field currents of the generator and the electric motors. According to the invention, the control means comprises a device for measuring the speed of the internal combustion engine, a device for indicating the appropriate eed for the engine as a function of the delivery of the engine fuel injection pump and means responsive to the diiterence between the actual speed of the engine and the appropriate speed indicated, said responsive means controlling a device governing the held currents of the generator and of the electric motor or motors.

The invention is hereinafter described with reference to the accompanying drawing, which represents diagrammatically a suitable example of embodiment.

The control means represented in the drawing comprises an accelerator pedal 1 actuated by the person operating the control means. The pedal it is operably connected to a hydraulic cylinder 2, pressure from which is transmitted through a pipe 2.: to act upon a piston 3 slidable in a cylinder 3a against the action of a return spring 4. The piston 3 is rigidly connected on one side to a roller-fitted finger 5 for actuating a cam s which serves to regulate the delivery of the engine i lection pump (not shown). On the other side, the piston 3 is rigidly connected to a rod '7 which regulates he compression of a spring 8 inside a sheath 9. The initial compression of the spring 2 can be regulated by means of a screwed bush to through which the rod '7' enters the sheath 9, the spring 8 pressing against the inner end of the bush, the position of which can be fixed by a loclr nut The sheath 9 is rigidly connected to a distributor valve slidabie a ported cylinder 13, and also to a flexible diaphragm id. The wall of the cylinder 13 comprises a series of ports 15 connected to a compressed air or other fluid reservoir to through a pipe 165:, and another series of ports 17 connected by a pipe 17a to a fluid-operated bellows device 13 for controlling the field currents of the generator and the electric motors. When the control device is in equilibrium, the ports 17 are closed by the distributor valve 32, as represented "n he drawing. The diaphragm casing is provided with two small openings To communicating with a space on one side of the diaphragm 1d, this space open to the ambient air. A space 21 on the other side of the diaphragm is connected, as by a pipe screwed into the hole 21a, to the suction side of the generator cooling fan wheel (not shown). Since the depression at the suction inlet of the fan wheel is a funcvalve is allowed to move bacir by the diaphragm tion of the speed of the internal combustion engine by which the generator is driven, the diaphragm 14 con stitutes a device for measuring the speed of the engine shaft. The fact that the pressure of the ambient air is admitted into the space 2d and a relative depression is admitted into the space 21 renders this measuring device particularly simple, while being independent of variations of the barometric pressure. The depression created in the space 21 relative to the space 2r"; has the effect of exerting a pull upon the distributor valve 12 and the sheath 9. This pull is counterbalanced in the state of equilibrium, as represented in the drawing, by the compression of the spring 8.

When the position of the piston 3 is changed by pressure upon the pedal 1, the position of the earn 6, which regulates the delivery of the engine fuel injection pump, is changed and at the same time the compression of the spring 8 is changed. As already stated, the compression of the spring 8 must counterbalance the relative depression in the space 2i, in the state of equilibrium. Now this depression is a function of the speed of the internal combustion engine, so that an appropriate speed (determined by the compression of the spring 8) can be selected at will for every rate of delivery of fuel by fitting a cam 6 of appropriate profile.

Since to each rate of fuel injection there corresponds an optimum speed of the internal combustion engine at which its thermal efiiciency is highest, the profile of the cam 6 can therefore be established in such a way that these optimum conditions of output are always fulfilled. if it is required that the improved control means shall serve to equip groups using internal combustion engines of dinerent types, not all having the same characteristics of fuel consumption and speed, the only element to changed is the cam 16, the profile of which can be made to measure at relatively low expense.

When the appropriate speed determined by the compression of the spring 8 is lower than the actual speed of the engine, the distributor valve 12 is pulled along by the diaphragm l4 bending towards the space 21, and it opens the ports 17 in the cylinder 13. Due to this fact the pneumatic bellows device 18 is placed in communication With the compressed air reservoir 16 and reduces the value of a resistance 22, for example a carbon stack, connected in series with the field Winding 23 of the generator 2'), and then increases the value of a similar resistance 24 in series with the field windings 25. and 26 of the electric motors 23, Due to this fact the generator is slowed down until it reaches the appropriate speed, when the ports 17 will again be closed by the distributor valve 12.

If on the other hand, the appropriate speed imposed by the compression of the spring 5; is greater than the actual speed of the internal combustion engine, the distributor Z tbending towards the space 2%, and it uncovers the ports i? in the cylinder 23, but so as to put them into communication with the space Due to this fact, the pressure of the bellows device 13 decreases, causing an increase in the resistance 22 in series with the field winding 23, which results in decreasing the load upon the generator 27 and permits it to increase speed until the distributor valve again occupies its position of equilibrium. in order to avoid hunting in the control procedure described above, the pipe lia connecting the bellows device 18 with the ports 17 may be formed with a constriction constituted for example by a small hole in a washer obstructing the pipe. The screwed bush lb described above may serve for example for regulating the idling speed of the internal combustion engine.

What l claim and desire to secure by Letters Patent is:

l. in or for a power system comprising an internal 3 combustion engine, an electric generator connected in driven relationship with said internal combustion engine, and an electric motor supplied with current from sai generator, said generator and said motor having armature windings and separate field windings, control means comprising a device for controlling the supply of fuel to said engine, means for positioning said fuel controlling device, a device responsive to a condition which is a function of the actual speed of said engine, s-aid condition being the air pressure on one side of a fan driven by said engine, a device for indicating an appropria;e engine speed as a function of the rate of delivery of fuel to said engine, and means responsive to the difference between the actual speed of said engine and the appropriate speed indicated, said last named means including a device governing the field currents of said generator and of said electric motor.

2. In or for a power system comprising an electrical generator, an internal combustion engine drivingly connected to said generator, said generator having a cooling fan and separate armature and field windings, a plurality of electric motors having separate armature and field windings, said armature windings being supplied :with cur- Trent from said generator, control means comprising a transducer for controlling the position or" a device regulating the supply of fuel to the engine, a pressure responsive device connected to the suction side of the generator cooling fan, a device for indicating an appropriate engine speed as a function of the rate of delivery of fuel to the engine, and a fluid pressure operated device governed by the difference between the actual speed of the engine and the appropriate speed indicated to vary the field currents of the generator and of the electric motors.

Control means according to claim 2 wherein the device regulating the supply of fuel to the engine comprises a cam profiled to regulate the delivery from a fuel injection pump to the engine to operate the engine at optimum thermal efliciency for any given speed.

A power system control device comprising :1 hollow cylindrical member having a hydraulic cylinder at one end and a ported valve chamber at the other end, a piston within said hydraulic cylinder, a piston rod extending through both end walls of the hydraulic cylinder, a port for the passage of hydraulic fluid in the cylinder wall behind said piston, a cam roller on the end of the piston rod protruding out of said cylindrical member for bearing on cam, a compression spring surrounding the other end of said piston rod within said cylindrical member and bearing against the adjacent end wall of the hydraulic cylinder, said valve chamber having two series of ports disposed along its length, a distributor valve in said valve chamber adapted at one end of its stroke to connect the two series of ports together and at the other end of its stroke to connect one series of ports to exhaust, said distributor valve having extensions at each end, that at the outer end being connected to a pressure responsive flexible diaphragm supported within a chamber venting on one side to atmosphere and adapted to be connected on the other side to a source of diiierential pressure, the inner end of the piston and the distributor valve extension be ing arranged in telescopic relation and being connected together by a compression spring.

5. A control device according to claim 4- comprising :a lockable screwed bush for regulating initial compression .of said last mentioned spring.

6. In or for a power system comprising an electrical generator, an internal combustion engine drivingly connected to said generator, said generator having a cooling fan and separate armature and field windings, and at least one electric motor having an armature winding and a field winding, said armature winding being supplied with current from said generator, control means comprising hydraulic means 'for positioning a device regulating the output of an engine fuel injection pump, a pressure responsive flexible diaphragm subjected on one side to the suction of the generator cooling fan and actuating a dis- 4 tributor valve, resilient means interconnecting said abovementioned device and said distributor valve to vary th meet of the flexible diaphragm according to tr e position of said device, and a fluid pr ssure operated device conrolled by said distributor valve to vary the field currents of the generator and electric motor.

7. Control means according to claim 6 wherein according to its position, said distributor valve selects between iuid pressure vents to atmosphere, sealing means, and connection to a source of fluid pressure.

8. in or for a power system comprising an electrical generator, an internal combustion engine drivingly connected to said generator, said generator having a cooling fan and separate armature and field windings, a plurality of electric motors having separate armature and field windings, two variable resistances operable by a common fluid pressure operated device, a source of electromotive force, electric cables connecting the generator field winding and one of said variable resistances in series with said urce of elcctromotive force, and electric cables connecthe motor field windings in parallel with each other in series with the other of variable resistances and said source of electromotivc force, control means comprising cam regulating the delivery of an engine fuel injection pump, hydraulic means for positioning said cam, a pressure responsive flexible diaphragm subjected on one side to the suction of the generator cooling fan on the other side to atmosphere, and actuating a distributor valve, pro-adjustable resilient means interconnecting said means for positioning said cam with said distributor valve to vary the effect of the suction on the flexible diaphragm according to the position of the cam, said distributor valve, according to its position, selecting between venting said fluid pressure operated device to at mosphere, sealing it off, and connecting it to a source of fluid pressure, in which last case the lluid pressure operated device reduces the value of the resistance in series with the generator field and then increases the value of the resistance in series with the motor fields.

9. A control device for at least one electric motor supplied with current by an electric generator, said generator being driven by an internal combustion engine, said motor and said generator having armature windings and field windings, said control device consisting of a casing within which are disposed in interconnected relationship a fluid pressure distributor valve, a pneumatic pressure responsive device, a speed control device and a device for selectively setting the fuel supply of the said engine; said fiuid pressure distributor valve actuating a control device for regulating the current in said field windings and being connected to said pneumatic pressure responsive device; pressure transmitting means between said pneumatic pressure responsive device and one side of a fan system driven by said engine; said fluid pressure distributor valve being also connected to one end of said speed control device; the other end of said speed control device being resiliently and adjustably connected to the said device for selectively setting the fuel supply of the internal combustion engine.

10. A control device for at least one electric motor supplied with current by an electric generator driven by an internal combustion engine provided with a device for independently regulating the supply of fuel thereto, said motor and said generator having armature windings and field windings, said control device comprising: a casing including a iiuid pressure distributor valve actuating a control device for regulating the current in said field windings, said distributor being connected to the moving part of a pneumatic pressure responsive measuring deice of the speed of the generator, said moving part of the measuring device being comprised in said casing, said dis ibutor being also connected to one end of speed control device comprised in said casing the other end of said speed control device being positioned by a device controlling the fuel supply of the internal combustion engine; said measuring device, fluid pressure distributor valve, speed control device and device for controlling the fuel supply being disposed in linear alignment within said casing.

11. A control device for one or more electric motors supplied with current by an electric generator having a cooling fan, said generator being driven by an internal combustion engine having a device for setting the supply of fuel to said engine, said motors and said generator having armature windings and field windings, said control device consisting of a casing comprising a fluid pressure distributor valve actuating a control device for regulating the current in said field windings, said distributor valve being connected on one side to the moving part of a pneumatic pressure responsive device connected to one side or a fan driven by said engine, said moving part of the pneumatic pressure responsive device being comprised in said casing, said distributor being connected on the other side to one end of speed control device comprised in said casing, the other end of said speed control device being positioned by a device controlling the fuel supply of the internal combustion engine resilient means between said ends of said speed control device.

12. A control device for one or more electric motors supplied with current by an electric generator having a cooling fan, said generator being driven by an internal combustion engine having a device for regulating the supply of fuel to said engine, said motors and said generator having armature windings and field windings, said control device consisting of a casing comprising a fluid pressure distributor actuating a control device for regulating the current in said field windings, said distributor being connected on one side to a diaphragm closing a space practised in said casing and connected to one side of the generator cooling fan, said distributor being connected on the other side to one end of a speed control device comprised in said casing, the other end of said speed control device being positioned by a device controlling the fuel supply of the internal combustion engine, said ends of said speed control device being resiliently connected.

13. A control device for one or more electric motors supplied with current by an electric generator driven by an internal combustion engine having a device for regulating the supply of fuel to said engine, said motors and said generator having armature windings and field windings, said control device consisting of a casing comprising a fluid pressure distributor actuating a control de vice for regulating the current in said field windings, said distributor being connected on one side to the moving part of a measuring device of the speed of the generator, said moving part of the measuring device being comprised in said casing, said distributor being connected on the other side to one end of a spring comprised in said casing, the other end of said spring being fixed to a rod operated by a pedal, said rod operating a cam controlling the fuel supply of the internal combustion engine.

14. A control device for one or more electric motors supplied with current by an electric generator driven by an internal combustion engine having a device for selectively setting the supply of fuel to said engine, said motors and said generator having armature windings and field windings, said control device consisting of a casing comprising a fiuid pressure distributor actuating a control device for regulating the current in said field windings, said distributor being connected on one side to the moving part of a measuring device of the speed of the genera tor, said moving part of the measuring device being comprised in said casing, said distributor being connected on the other side to one end of speed control device comprised in said casing, the other end of said speed control device being connected to a device comprising a cam controlling the fuel supply of the internal combustion engine, said cam being profiled to regulate the delivery from a fuel injection pump as calculated from the curve of optimum thermal eificiency for any given speed.

15. A control device for one or more electric motors supplied with current by an electric generator driven by an internal combustion engine having a device for regulating the supply of fuel to said engine, said motors and generator having armature windings and field windings, said control device consisting of a casing comprising a fiuid pressure distributor valve connected on one side to the moving part of a measuring device of the speed or" the generator, said moving part of the measuring device being comprised in said casing, said distributor being connected on the other side to one end of a speed control device com rised in said casing, the other end of said speed control device being connected to a device selectively setting the fuel supply of the internal combustion engine, said fluid pressure distributor comprising in a cylinder practised in said casing a valve, first connection means allowing a compressed fluid reservoir to communicate with one side of the valve, second connection means allowing uncompressed fiuid to communicate with the other side of the valve and third connection means communieating with ports practised in said cylinder and with a pneumatic pressure responsive device controlling a first variable resistance inserted into a circuit feeding the field windings of the generator and a second variable resistance inserted in a circuit feeding the field windings of the motor or the motors, said first variable resistance diminishing its resistance value and said second variable resistance increasing its resistance value when the pneumatic pressure in the pressure responsive device increases.

References Cited in the file of this patent UNITED STATES PATENTS 

1. IN OR FOR A POWER SYSTEM COMPRISING AN INTERNAL COMBUSTION ENGINE, AN ELECTRIC GENERATOR CONNECTED IN DRIVEN RELATIONSHIP WITH SAID INTERNAL COMBUSTION ENGINE, AND AN ELECTRIC MOTOR SUPPLIED WITH CURRENT FROM SAID GENERATOR, SAID GENERATOR AND SAID MOTOR HAVING ARMATURE WINDINGS AND SEPARATE FIELD WINDINGS, CONTROL MEANS COMPRISING A DEVICE FOR CONTROLLING THE SUPPLY OF FUEL TO SAID ENGINE, MEANS FOR POSITIONING SAID FUEL CONTROLLING DEVICE, A DEVICE RESPONSIVE TO A CONDITION WHICH IS A FUNCTION OF THE ACTUAL SPEED OF SAID ENGINE, SAID CONDITION BEING THE AIR PRESSURE ON ONE SIDE OF A FAN DRIVEN BY SAID ENGINE, A DEVICE FOR INDICATING AN APPROPRIATE ENGINE SPEED AS A FUNCTION OF THE RATE OF DELIVERY OF FUEL TO SAID ENGINE, AND MEANS RESPONSIVE TO THE DIFFERENCE BETWEEN THE ACTUAL SPEED OF SAID ENGINE AND THE APPROPRIATE SPEED INDICATED, SAID LAST NAMED MEANS INCLUDING A DEVICE GOVERNING THE FIELD CURRENTS OF SAID GENERATOR AND OF SAID ELECTRIC MOTOR. 